JAMB - Physics (1991 - No. 8)
A 20kg mass is to be pulled up a slope inclined at 30o to the horizontal. If the efficiency of the plane is 75%, the force required to pull the load up the plane is [g = 10ms-2]
13.3N
73.5N
133.3N
53.2N
설명
Efficiency = m.A x \(\frac{1}{V.R}\) X 100%
75 = \(\frac{20 \times 10}{effort}\) x \(\frac{1}{\frac{g}{sin\theta}}\) x 100%
Effort = 133.3N
75 = \(\frac{20 \times 10}{effort}\) x \(\frac{1}{\frac{g}{sin\theta}}\) x 100%
Effort = 133.3N